A systematic review of the safety and effectiveness of laser and light therapies for the treatment of pigmented purpuric dermatoses.

Pigmented purpuric dermatoses (PPD) represent a group of chronic skin disorders distinguished by small hemorrhagic spots and alterations in pigmentation. These conditions frequently resist standard therapies, such as topical corticosteroids and systemic drugs. This systematic review evaluates the safety and effectiveness of light and laser treatments for patients with various types of pigmented purpuric dermatoses. We searched the PubMed, Scopus, and Web of Science databases on 18 March 2025, in accordance with PRISMA guidelines. We examined studies that utilized light therapy and laser therapy for each type of pigmented purpuric dermatosis and analyzed the data based on treatment modality. We evaluated study quality based on design using appropriate assessment tools. Our initial search yielded 98 studies, of which 30 met our inclusion criteria, encompassing 98 cases. Various treatments were evaluated, including NB-UVB, PUVA, IPL, PDT, and lasers such as PDL, fractional (non-ablative 1540 nm erbium glass laser), and excimer lasers. NB-UVB was the most commonly used, showing consistent efficacy in improving pigmentation and pruritus across different PPD subgroups. PUVA also demonstrated significant clinical benefits. Among laser treatments, PDL was particularly effective in targeting vascular lesions, while fractional (non-ablative 1540 nm erbium glass laser) and excimer lasers achieved good lesion clearance with minimal side effects. Light and laser treatments have demonstrated effective results in addressing various types of pigmented purpuric dermatoses, particularly in more challenging cases. NB-UVB, PUVA, PDL, fractional laser, and excimer laser have achieved satisfactory outcomes with minimal side effects. Despite these promising results, clinical trials with larger populations are essential to confirm this data. The results of this study can serve as a useful guide for future research on the efficacy and safety of light- and laser-based therapies for the treatment of patients with pigmented purpuric dermatoses. What is known about this topic Pigmented purpuric dermatoses (PPD) are long-lasting skin conditions characterized by small bleeding spots and changes in skin color, which often do not respond well to standard treatments such as topical corticosteroids and systemic agents. Light- and laser-based therapies targeting vascular and inflammatory components have shown promising results in the treatment of various skin diseases, including PPD. However, previous studies have provided incomplete information, making it difficult to comprehensively understand the effectiveness, safety, and suitability of these treatments for different types of PPD. What this article adds This systematic review combines data from 30 studies involving 98 patients and provides a comprehensive evaluation of light- and laser-based treatments for PPD. Key findings include the high efficacy of NB-UVB and PDL with minimal side effects. The study also identifies important knowledge gaps, such as the need for more large-scale randomized trials and consistent treatment guidelines, while offering practical advice for physicians and encouraging further research to verify long-term results and improve treatment methods.